Study of flow dynamics in complex vessels using Doppler optical coherence tomography

Abstract

Doppler optical coherence tomography (DOCT) was applied to non-invasive monitoring of multi-dimensional velocity profiles within complex geometry vessels. The effect of channel geometry on the flow dynamics at different inlet flow rates was studied. We investigated the flow dynamic regime arising at the junction of T- and Y-shaped samples and vessels with aneurism. We show that at constant input volume flow rate, the distribution of flow velocities measured along a cross-sectional plane orthogonal to the inlet arm, located at 20 mm off the junction, exhibited stationary and laminar behaviour. A non-homogeneous distribution of flow velocity along a junction cross-section plane is presented. Finally, we demonstrate the feasibility of DOCT for mapping the velocity profiles along the vessels' junction with a spatial resolution of about 10 × 10 × 10 µm3 and a minimum detectable velocity of about 2 mm s−1.

Quantification of cell-free layer thickness and cell distribution of blood by optical coherence tomography

“…Potential applications in blood monitoring also include measuring hemoglobin 7 and glucose 8 concentrations. The microflows have been extensively studied in complex vessels by Doppler OCT. [9][10][11][12][13] The spatial distribution of RBCs in microchannels has been previously evaluated with OCT. 14,15 Due to an insufficient axial resolution of the used OCT systems, the thickness of a CFL has not been measured previously.…”

Quantitative analysis of optical properties of flowing blood using a photon-cell interactive Monte Carlo code: effects of red blood cells’ orientation on light scattering

“…For the first condition, we use Eq. (8). U pciMC ðx; y; zÞ ¼ ð0; U x ; U y ; U z Þ is translated to U pciMC ðr; s; tÞ ¼ ð0; U r ; U s ; U t Þ by the following process:…”

“…5 Understanding the optical properties of flowing blood with respect to these physiological parameters is, therefore, important for establishing a method for quantitative monitoring. As for direct imaging of blood flow, optical coherence tomography has been widely applied, [6][7][8] while for the theoretical approach Roggan 9 and Yaroslavsky 10-12 measured the absorption and scattering constants μ a , μ s and the anisotropy factor g of human blood by inverse Monte Carlo (MC) simulations in various physiological conditions. For developing a photon propagation model in blood based on MC simulation, the phase function derived using the Mie, Rayleigh-Gans, or straight-ray theory has been developed and utilized.…”

Application of optical coherence tomography for imaging of scaffold structure and micro-flows characterization

“…Doppler OCT, an extension of conventional OCT, allows to measure fluid flow velocity at discrete spatial locations and monitor the turbulence and laminar multidimensional velocity profiles in complex micro-channels [18,19]. In current report we applied the conventional OCT for the purpose of scaffold structure imaging.…”